In recent years, a semiconductor device having a plurality of circuits integrated over an insulated surface and various functions has been developed. Further, development of a semiconductor device capable of wireless data transmission/reception by providing an antenna has been advanced. Such a semiconductor device is referred to as a wireless chip (also referred to as an ID tag, an IC tag, an IC chip, an RF (Radio Frequency) tag, a wireless tag, an electronic tag, and an RFID (Radio Frequency Identification) tag), and is already introduced to a part of the market.
Many of these semiconductor devices that have already been put into practical use have a circuit using a semiconductor substrate such as a Si substrate (also referred to as an IC (Integrated Circuit) chip) and an antenna, and the IC chip includes a memory circuit (also referred to as a memory), a control circuit and the like. In particular, by providing a memory circuit which can store much data, a high-value-added semiconductor device providing higher performance can be provided. In addition, such semiconductor devices are required to be manufactured at a low cost. In recent years, an organic TFT, an organic memory and the like using an organic compound for a control circuit, a memory circuit and the like have been actively developed (Reference 1: Japanese Patent Application Laid-Open No. 2002-26277).
As a memory circuit, a DRAM (Dynamic Random Access Memory), an SRAM (Static Random Access Memory), an FeRAM (Ferroelectric Random Access Memory), a mask ROM (Read Only Memory), an EPROM (Electrically Programmable Read Only Memory), an EEPROM (Electrically Erasable and Programmable Read Only Memory), a flash memory and the like are given. Among them, a DRAM and an SRAM are volatile memory circuits in which data is erased when the power is turned off so that it is necessary to write data every time the power is turned on. An FeRAM is an involatile memory circuit and uses a capacitor element including a ferroelectric layer so that manufacturing steps thereof are increased. A mask ROM has a simple structure, however, data is required to be written during the manufacturing steps and cannot be additionally written. An EPROM, an EEPROM, and a flash memory are involatile memory circuits; however, an element having two gate electrodes are used, and thus, the manufacturing steps are increased.
On the other hand, a memory circuit using an organic compound is formed by using a memory element in which an organic compound is provided between a pair of electrodes. When a thickness of the organic compound layer is made thick, a current does not easily flow so that a drive voltage for writing and reading is increased.
In view of the foregoing problems, it is an object of the present invention to provide an involatile memory device, in which additional writing is possible other than in manufacturing steps and forgery and the like due to rewriting can be prevented, and a semiconductor device having the memory device. It is also an object of the present invention to provide an inexpensive involatile memory device and semiconductor device consuming low power.